Here’s a few ideas for gollums:

.Gollum, Riddle Master
Minion
Strength 5
Vitality 4
Site 3
When you play Gollum, spot a minion to reveal a card at random from the free peoples player’s hand. Add [x], where [x] is the twilight cost of the revealed card.
That’s a nice card right there.
.Gollum, Murderer
Minion
Strength 5
Vitality 4
Site 3
Lurker.
Each time another minion wins a skirmish, make Gollum strength +2.
I like that, too. That’s a good reverse-captain effect. And Gollum could become nasty in a swarm!
Thoughts?

Okay, so now here’s what I’ve got:

•Ungoliant, Gloomweaver
Minion-Spider
Strength 10
Vitality 10
Site 8
Captain. Enduring. Fierce.
When you play Ungoliant, you may play up to 2 Spiders from your discard pile.
Ouch! Possibly lose the fierce? Because it’s a really powerful card right now. I’ve also got some issues with the fact that Ungoliant was a First Age creature...you could easily change it to something else.
.Gollum, Riddle-Master
Minion
Strength 5
Vitality 4
Site 3
When you play Gollum, you may spot a minion to reveal a card at random from the free peoples player’s hand. Add [x], where [x] is the twilight cost of the revealed card.

.Gollum, Murderer
Minion
Strength 5
Vitality 4
Site 3
Lurker.
Each time a minion wins a skirmish, make Gollum strength +2 until the regroup phase.

Master of the Precious
Event • Skirmish
Exert the Ring-bearer to make Smeagol strength +X, where X is the Ring-bearer’s strength.

We Swears
Event
Fellowship: Spot Smeagol and discard a card from hand to draw a card.

Flickering Lights
Event • Fellowship
Exert a companion and add to remove a burden (limit 2).

• Through the Marshes
Condition • Support Area
Each time a burden is added, place a token here.
Maneuver: Remove 4 tokens from here to remove a burden.

Curse of the Black River
Condition-Support Area
When you play this condition, you may spot a companion. Each time that companion heals, add a token on this card. Skirmish: Remove a token from here to make a minion strength +2.

You could play it on the companion himself, making more obvious that HE is the one pumping the minions! Would be fun.

Caught in a Web
Condition
To play, spot a minion. Bearer must be a companion (except the Ring-Bearer). While skirmishing a spider, bearer is strength -1.

How about a (limit 1 per bearer)? Otherwise, with cycling, it could get pretty mean, sapping 4 strength of a companion until he dies, than sapping another one and so forth...

Out From the Shadows
Event-Shadow
Play a spider from your discard pile. Then, if the fellowship is at a forest site, add .

Cool, I like it!

Ferocity Born of Hatred
Event-Skirmish
Make a minion strength +2 (or +4 if skirmishing a wounded companion).

Could it be +4 if the Fellowship is at a forest site? Or have spiders get damage +1 while at forests?

Curse of the Black River
Condition-Support Area
When you play this condition, you may spot a companion. Each time that companion heals, add a token on this card. Skirmish: Remove a token from here to make a minion strength +2.
Nice. I would put a limit on it.
Caught in a Web
Condition
To play, spot a minion. Bearer must be a companion (except the Ring-Bearer). While skirmishing a spider, bearer is strength -1.
Limit per bearer, definitely...although Lost in the Woods can get pretty nasty too.
Out From the Shadows
Event-Shadow
Play a spider from your discard pile. Then, if the fellowship is at a forest site, add .
Nice! I love the tie-in to forests.
Ferocity Born of Hatred
Event-Skirmish
Make a minion strength +2 (or +4 if skirmishing a wounded companion).
Good card. Forest bonuses would be more along the lines of a card like "Fearful Mazes".